Small influence of parental educational level on the survival of children with leukaemia in The Netherlands between 1973 and 1979.

We studied the effect of parental educational level (PEL), an indicator of socio-economic status (SES), on survival of children with acute lymphoblastic (ALL) and non-lymphoblastic leukaemia (ANLL). All children with ALL and ANLL diagnosed in The Netherlands in the period 1973-1979, registered by the Dutch Childhood Leukaemia Study Group and followed until 1991 were included. Bone marrow and blood smears had been uniformly classified in a central laboratory; cases with acute lymphoblastic leukaemia (ALL) were subdivided into standard risk (SR) and high risk (HR). PEL, assessed as a risk indicator in a separately conducted population-based case-control study of the same children (response rate: 88%), was divided into low, when neither of the parents had more than elementary school or lower vocational education, and high when either had more. Children with SR ALL of high PEL parents had a slightly higher 10-year survival rate than of low PEL parents (58% versus 54%, P = 0.25), whereas survival for the latter increased more (P = 0.06) from a lower level in the period 1973-1975. However, children of low PEL parents with HR ALL and ANLL had a higher 10-year survival rate compared with children of high PEL parents (P = 0.10 and 0.22, respectively). Children without information on PEL, non-responders, migrants and with missing values exhibited slightly worse survival rates. The influence of PEL on survival of acute leukaemia in children in The Netherlands during 1973-1979 appeared small or even equivocal. Small differences in SES and optimal geographic and financial access to care, delivered through national treatment protocols, may be responsible for these results.